Rotary feeder



L. E. MYLTING ROTARY FEEDER Feb. 20, 1968 4 Sheets-Sheet 1 Filed NOV. 8, 1965 INVENTOR. 22, LAURITZ E. mums is ATTORNEYS Feb. 20, 1968 E. MYLTING 3,369,677

ROTARY FEEDER Filed Nov. 8, 1965 4 Sheets-Sheet 2 46 Q szeb INVENTOR. LAURITZ E. mums his ATTORNEYS Feb. 20, 1968 L. E. MYLTING 3,369,677

ROTARY FEEDER Filed Nov. 8, 1965 4 Sheets-Sheet 5 5 FIG. 4 I

A TTORNEYS United States Patent 3,369,677 RGTARY FEEDER Lauritz E. Mylting, Ardmore, Pa., assignor to Buell Engineering Company, Inc., Lebanon, Pa., a corporation of Delaware Filed Nov. 8, 1965, Ser. No. 506,802 6 Claims. (Cl. 214-17) ABSTRACT OF THE DISCLOSURE This invention relates to rotary feeders and, more particularly, to a novel and improved rotary feeder having a rotor mounting arrangement which considerably facilitates adjustment of the rotor to the shoe.

A significant problem with many presently known rotary feeders is the maintenance of proper adjustment between the rotor and the shoe which serves as a seal between the inlet to the feeder from the material supply and the interior and outlet of the feeder. The contacting surfaces or the rotor and shoe become worn relatively quickly by the abrading action of fine particles, thus necessitating frequent adjustment to close the space between the rotor and shoe formed by the wear. Adjustment, which is also necessary upon the initial installation and subsequent replacements of the rotor and shoe, necessitates shutdown of the feeder and, often, an entire production process for which the feeder is an important piece of apparatus. Adjustment of some types of feeders involves repeated trial and error manipulations, and the shutdown time can run to 'a matter of hours, a period of time which is very costly to the user, especially in terms of lost production.

For example, in one known type of adjustable rotor mounting each of the rotor shaft bearings are carried in a bearing housing which is supported by two pairs of diametrically opposite set screws. The set screws are arranged to provide vertical and lateral adjustment, by which precise alignment of the shoe axis and rotor axis can be provided. However, this arrangement requires trial and error movements, first vertically, then laterally, at each end of the rotor; each change in either the vertical or lateral direction changes the relative position between the rotor and shoe in the other direction. Accordingly, each adjustment in one direction requires a compensating change in the other direction. Because proper adjustment requires precision to, say, 0.0002 or 0.0003 in., many pairs of adjusting movements, often with operating tests between them, are sometimes needed to achieve proper functioning of the feeder.

The foregoing and other disadvantages of rotary feeders of the prior art are overcome, in accordance with the invention, by a novel and improved rotary feeder comprising a housing having on inlet and outlet, a shoe having an inlet passage and mounted in the housing adjacent the housing inlet, and a rotor rotatably mounted in the housing and in sealing engagement with the shoe. The rotor is mounted in the housing in such a way that it can be adjusted with respect to the shoe; in particular, the rotor mounting arrangement provides for adjustments consisting solely of pivotal movements of the rotor axis about pivot points spaced from the rotor and shoe axes and from the sealing surface of the shoe and linear translation of the rotor axis in a predetermined direction toward and away from the shoe.

In one embodiment, the rotor mounting arrangement comprises set screws installed radially, with respect to the shoe axis, in the housing at intervals to support and position each of the end members in which the rotor is journaled. One set screw at each end is located diametrically opposite from the shoe, is aligned on the bisector plane of the shoe, and is seated in the end member to provide for solely rotational movement of the end member with respect thereto. The end of this screw, that is, the point at which it is seated in the end member, provides the pivot point for the respective end member. The remaining three screws cooperate with the pivot point screw to provide pivotal movement of the end member about the pivot point screw and serve to fix the end member in its adjusted position.

In 'another embodiment of the invention, threaded studs on the housing are received in openings in housing end members, and set screws installed in the end members enter into predetermined ones of the openings. Corresponding openings remote from the shoe in each of the end members have an elongated slot which engages diametn'cally opposite edges of the stud and affords solely linear translation of the end member in a direction aligned with the longer axis of the slot. The remaini'ng openings in the end members are substantially larger than the studs and afford pivotal movement of the end member about the stud which is received in the slot.

The rotor mounting arrangement, in accordance with the invention, considerably facilitates adjustment of the rotor to the shoe by providing two support points for each end of the rotor to hold it in position while it is being fixed in place. In particular, adjustment is begun by loosening all of the adjusting elements, such 'as the set screws which are preferably used, to permit relatively free movement of the rotor. Using those set screws which provide for linear translation of the rotor axis, the rotbr is brought into tight engagement with the shoe. Engage ment of any part of the rotor with the shoe, during linear translation, will automatically induce pivotal movement of the rotor axis about the pivot points, so that the end result is tight engagement, in properly oriented position, of the rotor against the shoe.

After the above-described initial adjustment step'is completed, the lateral adjustment screws are tightened so that pivotal movement of the rotor axis, relative to the pivot points, is precluded. During this step of the adjusting procedure, the rotor axis is held in a fixed position, first, by the pivot points at each end, and secondly, by the centering action of the shoe, and the tightening of the lateral adjusting screws can, accordingly, be made without any danger of lateral displacement of the rotor.

After the lateral set screws are tightened down, the final step involves providing the required separation between the rotor and shoe to make the rotor relatively freely rotatable. This is accomplished by backing off the first set screw in a predetermined amount and then tightening down on the screw opposite from it.

For a better understanding of the invention, reference may be made to the following description of exemplary embodiments, taken in conjunction with the figures of the accompanying drawings, in which:

FIG. 1 is a plan view of one embodiment of the invention;

FIG. 2 is an end view in section of the embodiment of FIG. 1 taken generally along a plane represented by the lines 22 in FIG. 1 and in the direction of the arrows;

FIG. 3 is an end elevational view of the embodiment of FIG. 1, portions being broken away to illustrate certain parts;

FIG. 4 is a top view of another embodiment of the rotary feeder of the invention;

FIG. 5 is an end view in section of the embodiment of FIG. 4 taken generally along a broken plane represented generally by the lines 5-5 of FIG. 4 and in the direction of the arrows; and

FIG. 6 is a side view in section of the embodiment in FIG. 4 taken generally along a plane represented by the lines 66 of FIG. 4 and in the direction of the arrows.

The embodiment of the rotary feeder of the invention shown in FIGS. 1 to 3 comprises a housing 10 having a body 12, a spool piece 14 bolted to the top of the body and end members or end plates 16 and 16 fastened to the ends of the body. The spool piece 14 includes a tapered inlet opening 18 and is provided with a peripheral flange by which it can be attached to the outlet of a hopper or the like carrying the'material to be fed by the rotary feeder. In the lower part of the housing is a cylindrical outlet opening 20 which is surrounded by a flange 21 for securing the feeder to a pipe 22 into which the material is discharged.

Rotatably mounted within the housing by means of bearing assemblies 24 bolted to the end plates 16 and 16 of the housing is a rotor 26. The rotor includes a main shaft 28 journaled in the bearing assemblies 24, a central hub 30 installed on and fixed in place on the shaft 28, a series of radial walls 32, and a pair of circular end members 34. The rotor is thus provided with a number of compartments and, upon rotation by means of a chain or other suitable mechanism coupling a motor to the shaft, these compartments are carried, in succession, past the inlet opening 18 and are filled with material from the hopper. Upon further rotation, the material in each compartment empties by gravity through the outlet 20 and into the pipe 22 or other receiving element.

The periphery of the rotor 26 engages, in the region surrounding the inlet opening 18, a sealing shoe 38, which is mounted within the housing by means of blunt set screws 40, which hold the shoe in the desired orientation in the housing, and pointed set screws 42, which engage sloping notches 44 formed on flanges at the upper end of the shoe and clamp the shoe against the lower surface of the spool piece 14. The shoe 38 is provided with an inlet passage 39 to communicate the rotor compartments with the inlet 18 through the spool piece 14.

Referring particularly to FIGS. 1 and 3, the end members 16 and 16, which are preferably identical, thereby providing a cost-saving in the manufacture of the rotary feeder, are clamped to the ends of the housing body 12 by nuts threaded onto studs 46 secured to the housing and received in openings 48 in the end walls. The studs are of substantially smaller diameter than the openings, except for a stud, designated in the drawings by the reference numeral 46a, located at the lower right portion of the housing. The stud 46a is received in an elongated slot 48a having a width equal to the diameter of the stud. The major axis of the slot 46a is substantially parallel to a line which bisects the shoe 38 and passes through the shoe axis, that is, the center of curvature of the surface of the shoe which is engaged by the rotor. Accordingly, when the nuts which clamp the end wall members 16 and 16' to the housing are loosened, the end wall member can be pivoted about the stud 46a and can also be moved along a line toward and away from the rotor; however, lateral movement of the lower portion of the housing end wall members 16 and 16' is prevented by the engagement between the stud 46a and longer walls of the slot 48a.

Set screws 50 are installed in bosses 52 formed adjacent selected ones of the stud receiving openings 48. In particular, a set screw 50a enters vertically from below into the slot 48a and engages the stud 46a; horizontally, inwardly extending set screws 50b and 50c engage the upper and outermost studs 46b and 460, respectively, on the housing, and a set screw 50d enters vertically from above and engages the right, upper stud 46d. Each vertical pair of set screws 50a and 50d provides for vertical translation of the respective end wall members while the set screws 50b and 50c provide for rotational or pivotal movement and adjustment of the housing end Wall mem bers about the studs 46a. Adjustment of the rotor to the shoe utilizing the above-described rotor mounting arrangement is accomplished in a manner that will be described in detail hereinafter.

Referring next to FIGS. 4 to 6, another embodiment of the rotary feeder of the invention comprises a housing which consists of a body 102 and rotor mounting members 104 installed in openings at each end of the body 102. The body 102 is formed from two identical castings, each of which makes up a section on one side of a transverse bisector of the rotor, which are placed end to end and clamped together by bolts 106. This construction makes for particularly efficient casting and assembly procedures and enables a considerable reduction in the cost of manufacturing of the feeder.

As best shown in FIGS. 5 and 6, the interior of the housing body is generally cylindrical and each end of the housing body has an inwardly extending, circumferential flange 108 defining a circular hole 110. The rotor mounting members 10-!- are received in the openings 110, have outwardly extending flanges 111 which bear against the inner walls of the flanges 108, and are held in place by lock nuts 112. Nylon pellets 114 serve to secure the lock nuts 112 against rotation.

Installed in the outer end of each of the rotor mounting members 104 is a bearing assembly 116 which carries the shaft 118 of the rotor 119. A cavity formed in each member 104 receives a packing arrangement for closing off the interior of the feeder from the exterior. In both the embodiments of FIGS. 1 to 3 and the embodiment of FIGS. 4 to 6, the zone of the shaft bearings can be supplied with air at a pressure above the operating pressure of the feeder outlet in order to prevent the intrustion of material into the bearings.

Mounted within the feeder housing adjacent the inlet opening is a shoe 120, which is in the form of a segment of a cylinder, is of uniform thickness, and has an inlet passage 122 aligned with the inlet 124 into the housing. The shoe is positioned and clamped in place against the inner surface of the housing by set screws 126 (FIG. 5) which are installed at an angle in the housing body and bear against the longitudinal edges of the shoe.

Each of the rotor mounting members 104 is supported within the opening by two pairs of radially disposed, diametrically opposite set screws 130, 130a. The lowermost set screw 130a holding each member 104 has a spherical tip 131a which is received in a correspondingly spherical indentation 132 formed in the surface member 104. The remaining set screws in each end have blunt ends which bear directly against the cylindrical surface of the respective members 104.

In a manner similar to the rotor mounting arrangement of the embodiment of FIGS. 1 to 3, the rotor arrangement of the embodiment in FIGS. 4 to 6 enables (when the other three set screws are loosened) pivotal movement of each of the rotor mounting members 104 about the lowermost set screws 130a, and linear translation of the rotor toward and away from the shoe 120. However, the lower ends of the members 104 cannot be moved radially, being held in place by the engagement of the spherical tips 131 in the spherical indentations 132.

In both embodiments of the invention described above, and illustrated in the drawings, the preferred procedure for adjusting the rotor into proper engagement with the shoe is to first loosen all of the set screws and then tighten the set screw which will provide linear translation of the end member toward the rotor (set screw 130a in the embodiment of FIGS. 4 to 6 and set screw 50]) in the em bodiment of FIGS. 1 to 3) in a direction to move the rotor into tight engagement with the shoe, thereby causing the rotor to firmly seat itself against the surface of the shoe. Thereafter, the set screws which provide lateral movement of the end members and of the rotor axis are tightened to hold the rotor in place.

During the tightening of the lateral set screws, each end of the rotor is held at two points, one of the points being the point about which the rotor axis is pivotable, and the other point being the rotor axis which is retained in place by engagement of the rotor against the shoe. Thus, the lateral adjusting set screws can be brought into engagement without any significant danger of causing lateral movement of the rotor. In this regard, the slight movement and tightening in one direction when one set screw is adjusted can be compensated for by backing otf slightly on the first lateral set screw to be adjusted. Thereafter, the opposite set screw can be brought into engagement and then backed off very slightly. Finally, the two lateral set screws can be turned down slightly again, but to a degree less than the amount by which they were previously backed oft". At this point the rotor should be accurately positioned laterally with respect to the vertical axis, but a slight adjustment in the vertical direction, so that the rotor is not tightly against the shoe as it was when the initial adjustment of the first set screw was made, is needed. To provide a refinement of the vertical adjustment, the first set screw at each end to be adjusted (50d in FIGS. 1 to 3 and 130a in FIGS. 4 to 6) is backed off slightly to permit the rotor to move away from the shoe very slightly, and the diametrically opposite vertical set screw (50a in FIGS. 1 to 3 and upper screw 130 in FIGS. 4 to 6) is then tightened down to fix the rotor in place. Adjustment is then complete, and the feeder is ready for operation.

It will be understood that the above-described embodiment of the invention is merely exemplary and that those skilled in the art will be able to make many modifications and variations without departing from the spirit and scope of the invention. Accordingly, all such modifications are intended to be within the scope of the invention as defined in the appended claims.

I claim:

1. A rotary feeder comprising a housing having an inlet and an outlet, a shoe having an inlet passage mounted in the housing adjacent the inlet, a rotor having a shaft at each end, and a mounting assembly for each rotor shaft rotatably mounting it for adjustment of the rotor into proper sealing engagement with the surface of the shoe, each mounting assembly including an end journal member rotatably carrying the respective rotor shaft, first adjusting means for the end member coacting between the housing and the end member to adjust the rotor in a direction toward and away from the shoe generally on a line bisecting the shoe and passing through the shoe axis, and further coacting between the housing and the end member to provide a pivot point affording solely pivotal movement of the rotor axis about said pivot point, and each mounting assembly further including second adjustmg means for the respective end member coacting between the housing and the end member to adjust the rotor axis in a direction generally transverse to a line bisecting the shoe and passing radially through the shoe axis.

2. A rotary feeder comprising a housing having an inlet and an outlet, a shoe having an inlet passage mounted in the housing adjacent the inlet, a rotor having a shaft at each end, and a mounting assembly for each rotor shaft rotatably mounting it for adjustment of the rotor into proper sealing engagement with the surface of the shoe, each mounting assembly including an end journal member rotatably carrying the rotor shafts, and means adjustably mounting each of the end members on the housing, each mounting means including a first pair of set screws cooperating between the housing and the end member to adjustably position the end member III a direction generally on a line bisecting the shoe and passing through the shoe axis, a second pair of set screws coacting between the housing and the end member to adjustably position the end member in a direction transverse to a line bisecting the rotor and passing radially through the rotor shaft, and coacting means including one of the first set screws and carried by the end member and housing and spaced from the rotor and shoe axes and from the sealing surface of the shoe constituting a predetermined pivot point affording solely pivotal movement of the rotor axls thereabout.

3. A rotary feeder according to claim 1 wherein the housing includes a pair of identical wall members secured together in end to end relation and defining a cavity therewithin, the inner surfaces of the housing wall members cooperating to define a semi-cylindrical portion surrounding the inlet opening, and wherein the shoe is in the form of an. arcuate member of uniform thickness mounted in the housing and bearing against the semicylindrical housing wall portion, opposed end openings in the housing members, end members positioned in the end openings, and a rotor rotatably mounted in the end members for engagement with the inner surface of the shoe, the end members being adjustably mounted in the housing openings solely for selective pivotal movement of the rotor axis about a predetermined axis spaced from the rotor and shoe axes and from the inner surface of the shoe, and said predetermined axis being selectively movable solely along a predetermined line.

4. A rotary feeder according to claim 2, wherein said set screws are installed radially, with respect to the shoe axis, in the housing at intervals, one screw at each end of the housing being disposed in the plane bisecting the shoe and passing through the shoe axis and being located diametrically opposite the shoe, the said one screw being seated in the respective end members to provide solely rotational movement of the end member with respect thereto.

5. A rotary feeder according to claim 2 comprising threaded studs on the housing, openings in the end members received the studs, the set screws being installed in the housing and entering the openings, a corresponding opening remote from the shoe in each of the end members being an elongated slot engaging diametrically opposite edges of the stud received therein and affording solely linear translation of the end member along the longer axis thereof, the remaining ones of the end member openings being substantially larger than the studs and affording movement of the end members relative to the housing, and fasteners installed on the studs for securing the end members to the housing.

6. A rotary feeder according to claim 3, wherein the shoe is mounted in the housing solely by means of set screws installed in the housing wall members in engagement with the longitudinal edges of the shoe and aligned to urge the shoe into engagement with the said arcuate housing surface.

References Cited UNITED STATES PATENTS 2,538,320 1/1951 Mylting 222-368 X 2,766,911 10/1956 Greaves et al. 222368 X 2,888,175 5/1959 Harrison et a1 222-368 X ROBERT G. SHERIDAN, Primary Examiner. 

